/*
 * FreeRTOS memory safety proofs with CBMC.
 * Copyright (C) 2019 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * http://aws.amazon.com/freertos
 * http://www.FreeRTOS.org
 */

#include "FreeRTOS.h"
#include "queue.h"
#include "queue_init.h"
#include "tasksStubs.h"
#include "cbmc.h"

BaseType_t state;
QueueHandle_t xQueue;
BaseType_t counter;

BaseType_t xTaskGetSchedulerState( void )
{
    return state;
}

void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut )
{
    /* QueueSemaphoreTake might be blocked to wait for
     * another process to release a token to the semaphore.
     * This is currently not in the CBMC model. Anyhow,
     * vTaskInternalSetTimeOutState is set a timeout for
     * QueueSemaphoreTake operation. We use this to model a successful
     * release during wait time. */
    UBaseType_t bound;

    __CPROVER_assume( ( bound >= 0 && xQueue->uxLength >= bound ) );
    xQueue->uxMessagesWaiting = bound;
}

void harness()
{
    /* Init task stub to make sure that the third loop iteration
     * simulates a time out */
    vInitTaskCheckForTimeOut( 0, 3 );

    xQueue = xUnconstrainedMutex();
    TickType_t xTicksToWait;

    if( state == taskSCHEDULER_SUSPENDED )
    {
        xTicksToWait = 0;
    }

    if( xQueue )
    {
        /* Bounding the loop in prvUnlockQueue to
         * PRV_UNLOCK_QUEUE_BOUND. As the loop is not relevant
         * in this proof the value might be set to any
         * positive 8-bit integer value. We subtract one,
         * because the bound must be one greater than the
         * amount of loop iterations. */
        __CPROVER_assert( PRV_UNLOCK_QUEUE_BOUND > 0, "Make sure, a valid macro value is chosen." );
        xQueue->cTxLock = PRV_UNLOCK_QUEUE_BOUND - 1;
        xQueue->cRxLock = PRV_UNLOCK_QUEUE_BOUND - 1;
        ( ( &( xQueue->xTasksWaitingToReceive ) )->xListEnd ).pxNext->xItemValue = nondet_ticktype();

        /* This assumptions is required to prevent an overflow in l. 2057 of queue.c
         * in the prvGetDisinheritPriorityAfterTimeout() function. */
        __CPROVER_assume( (
                              ( UBaseType_t ) listGET_ITEM_VALUE_OF_HEAD_ENTRY( &( xQueue->xTasksWaitingToReceive ) )
                              <= ( ( UBaseType_t ) configMAX_PRIORITIES ) ) );
        xQueueSemaphoreTake( xQueue, xTicksToWait );
    }
}
